Research On Correlation Between Road Performance And Porosity Of Drained Asphalt Pavement

With the rapid development of China’s highway business and material living standards,people have put forward higher requirements for the quality of road use.Drained asphalt pavement has attracted the attention of many roadworkers because of its advantages such as noise reduction,water mist reduction,and anti-skid,but compared with ordinary dense graded asphalt pavement,drainage asphalt pavement has high construction temperature requirements,difficult construction,easy aging and water.Limitations such as destruction and easy clogging of gaps have greatly hindered the widespread promotion of drainage asphalt pavement.Therefore,a systematic and in-depth study on the composition,road performance,and void blocking behavior of the drainage asphalt mixture is of great practical significance for the popularization and application of drainage asphalt pavement.In this paper,different modifiers are selected to prepare high-viscosity modified asphalt,and the conventional properties of high-viscosity modified asphalt composed of different modifiers and modifier blending ratios are studied.The test results show that,compared with the improvement effect of ARA on asphalt performance,the improvement effect of ARA + SBS on asphalt performance is more significant.It is mainly reflected in the following two aspects:(1)Under the same blending ratio,the softening point and dynamic viscosity of ARA modified asphalt are lower than that of ARA + SBS modified asphalt at 60 ℃,and the difference between the two can be up to14.6 ℃ and 26015 Pa.s,which shows that the high temperature performance of ARA +SBS modified asphalt is better;(2)ARA + SBS high viscosity modified asphalt has better storage stability,and the surface of the asphalt is flat and free under 72 h of hot storage In the case of skin separation,the difference in softening point is still less than2.5 ℃.In addition,through experiment comparison,it is concluded that the optimal blending ratio of ARA + SBS modifier should be 9% + 4%.The effects of porosity on the road performance of the drainage asphalt mixture were studied by rutting test,water immersion Marshall test,freeze-thaw splitting test,low-temperature beam bending test and anti-sliding performance test.The test shows that(1)the high temperature performance,water stability and low temperature crack resistance of the mixture decrease with the increase of the void ratio of the mixture;(2)compared with the ordinary dense graded mixture,the Both the structural depth and the friction coefficient have been greatly improved.Among them,the structural depth of the drainage asphalt mixture increases with the increase of the porosity,and the friction coefficient of the mixture has no obvious correlation with the porosity.The main factors for the clogging of the drainage asphalt mixture are analyzed,and the behavior of the clogging behavior of the mixture is studied from the aspects of load effect,compaction temperature and clogging.The test results show that(1)the porosity of the mixture decreases with the increase of the number of compactions(the Marshall compactor is used to adjust the number of compactions),and the change of the porosity tends to be gentle when the number of compactions exceeds 110,and this There is no difference in the change law due to the difference of the void ratio of the mixture;(2)The suitable compaction temperature of the mixture varies with the change of the void ratio.The larger the void ratio,the wider the suitable compaction temperature range,the more the void ratio Smaller,the narrower the suitable compaction temperature range is,that is,the smaller the porosity of the mixture is,the higher the temperature sensitivity;(3)The permeability coefficient of the mixture is affected by the size,type,and particle size of the plugging mass,and the analysis test As a result,it was found that the larger the porosity of the mixture,the stronger the drainage performance and anti-clogging performance.